We try to answer all questions within a reasonable time but situations occur in which some questions go unanswered. Reasons vary from no expert available (all are volunteers), experts may be on vacation, questions may not show an attempt to solve (we HELP, not DO, homework), and some questions get lost in the shuffle. Most students are aware of this and they repost if the question goes to page 2 or page 3 and remains unanswered.